With its congregation dating to 1783, the Cathedral is associated with the first organized Anglican parish in Ontario. Started in 1825, St. George's replaced a smaller structure built a short distance away in 1792. The core of the existing church was built of stone to the design of Kingston architect Thomas Rogers in 1825. The building was substantially enlarged in the 1840s with the addition of a nave bay, a large clock tower and an entrance portico comprised of a pediment supported by four columns. Completely gutted by fire in 1899, the church was quickly rebuilt under the direction of Joseph Power & Son. In 1975, the City of Kingston designated the church under the Ontario Heritage Act and, in 1981, the Ontario Heritage Trust secured a heritage easement on the building.